Clinical investigations are underway to determine the early natural history and possible causes of drusenoid macular degeneration. Drusen, serous and hemorrhagic detachments of the retina and retinal pigmented epithelium, and choroidal neovascularization are manifestations of macular degeneration and will be studied by serial recordings of the anatomical appearance and visual function of eyes at high risk of developing disease. Results will be compared with those obtained from fellow eyes with more advanced disease, age matched normals, and those with other maculopathies including that of retinitis pigmentosa. Serum, and in some case, 24-hour urine, levels of hormones including melatonin, cortisol, thyroid and zinc are being determined. By emphasizing studies of affected and unaffected family members and using various genetic markers such as HLA antigens, it is hoped that those factors materially associated with the appearance and/or progression of various retinal degenerative conditions will be elucidated. Melatonin rhythms are being studied in individuals blinded from various causes. Blind subjects can be either free-running or entrained to time cues other than the dawn-dusk cycle.